"…and she decided to hire me to install the other one in the snow cave 'cause no-one else was available", Sans explained to his brother.
What he did not bother to add was that Alphys knew if something went wrong and he couldn't get her machine to work, he would be able to go find her for help immediately.
"SEEING NEW THINGS AND MEETING NEW PEOPLE CAN ONLY DO YOU GOOD!" Papyrus commented. "AT LEAST IT WILL BE BETTER THAN STAYING AT GRILLBY'S ALL DAY."
The older skeleton wanted to argue that he did leave Grillby's to go to work several times a day, but had to admit the younger one had a point.
"IS THE SNOW CAVE LIKE SNOWDIN THOUGH?"
"dunno. wanna come check it out?"
"I CAN'T JUST TAKE A DAY OFF", Papyrus stated. "I-WE HAVE IMPORTANT WORK TO DO, KEEPING THE MONSTERS SAFE."
Not for the first time, it was obvious to Sans that his brother was actually better at being a responsible adult than he was ; however now he finally had the energy to care about it.
He was sincerely and absolutely proud of Papyrus, that never changed. But wow, was Sans really lagging behind in a lot of ways. He earned more money, sure, but everything else…
"well alright then. i'mma go pack my bag."
"MAYBE I'LL DROP BY AFTER YOU'VE INSTALLED DR. ALPHYS' DEVICE."
"yeah", Sans said, "just-"
"DON'T HURT YOURSELF ON THE WAY DOWN, I KNOW", Papyrus finished.
"man, i really gotta be faster."
Since school was out for the afternoon that day, Toriel and Frisk decided to take their guests to the park. Bubbles started playing with the echo flowers immediately after being told what they were. Toriel explained how the flowers had to be moved from the Underground to the Surface.
"Does your kingdom also have unique flora?" she asked Lorena.
"We do have colour-changing fungus that has appeared in some parts of our cave some centuries ago. People use them for art. Rocky especially. She's very good at it."
"I would love to see it."
A few minutes later, they ran into- well, more exactly, Papyrus and Undyne ran into them while jogging through the park together. Toriel introduced them to Lorena & Bubbles.
Everyone kept walking through the park together until they found a bench the two boss monsters and their children sat on. Then Bubbles stood up again to talk to the nearest echo flower.
"It was a tradition in Waterfall to whisper your wishes to these flowers", Undyne explained while taking the elemental's place on the bench. "Well, since we moved them to the Surface we can do that again."
"I WISH WE'D KEPT THE SNOWDIN TRADITIONS TOO", Papyrus said. "I MISS THE GIFT TREE. HUMANS HAVE SOMETHING SIMILAR, BUT THEY ONLY PUT IT UP ONCE A YEAR! HOW PREPOSTEROUS! WHY WOULDN'T YOU WANT A PRETTY GIFT TREE IN YOUR TOWN ALL YEAR ROUND? WHY ARE THEY LIKE THIS?"
Undyne stood up, stated she would be right back then bolted out of the park so fast she was like a distant blue and red blur disappearing on the horizon.
"Where'd she go?" Bubbles asked.
The echo flower near her repeated her question over and over.
The conversation resumed for a little while. Then the fish monster came back, casually carrying the uprooted Snowdin gift tree on her shoulder and looking for a good spot to plant it. Papyrus' eye sockets were full of stars.
He did his best to modify the shape of his summoned bone so that it resembled a shovel, then dug a hole his friend could plant the tree in. Said tree had lost half its decorations during the trip from Snowdin ; Frisk offered to go find new ones to bring it back to its former glory.
"WOWIE!" Papyrus exclaimed as he put the dirt he previously dug up back into the hole to cover the roots. "ALL THIS TIME, ALL I HAD TO DO WAS TALK ABOUT IT!"
"Hey, anything for my best friend!" Undyne smiled. "And I already have a gift for you!"
"OH?"
She grabbed his arm in one hand and gave him a noogie with the other, which caused the skeleton's face to do that thing where it looked like he suddenly grew eyes.
"OH NO! IT WAS A TRAP!"
She finally released him, laughing her head off.
"But seriously though, I gotta find you a real gift someday."